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Diffstat (limited to 'malloc')
-rw-r--r--malloc/malloc.c63
1 files changed, 48 insertions, 15 deletions
diff --git a/malloc/malloc.c b/malloc/malloc.c
index 2cf2025237..03d68b75e7 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -1691,14 +1691,11 @@ thread_atfork_static(ptmalloc_lock_all, ptmalloc_unlock_all, \
initialization routine, then do the normal work. */
static Void_t*
-#ifdef _LIBC
-malloc_hook_ini(size_t sz, const __malloc_ptr_t caller)
-#else
#if __STD_C
-malloc_hook_ini(size_t sz)
+malloc_hook_ini(size_t sz, const __malloc_ptr_t caller)
#else
-malloc_hook_ini(sz) size_t sz;
-#endif
+malloc_hook_ini(sz, caller)
+ size_t sz; const __malloc_ptr_t caller;
#endif
{
__malloc_hook = NULL;
@@ -1746,10 +1743,33 @@ __malloc_ptr_t weak_variable (*__memalign_hook)
= memalign_hook_ini;
void weak_variable (*__after_morecore_hook) __MALLOC_P ((void)) = NULL;
+/* Whether we are using malloc checking. */
+static int using_malloc_checking;
+
+/* A flag that is set by malloc_set_state, to signal that malloc checking
+ must not be enabled on the request from the user (via the MALLOC_CHECK_
+ environment variable). It is reset by __malloc_check_init to tell
+ malloc_set_state that the user has requested malloc checking.
+
+ The purpose of this flag is to make sure that malloc checking is not
+ enabled when the heap to be restored was constructed without malloc
+ checking, and thus does not contain the required magic bytes.
+ Otherwise the heap would be corrupted by calls to free and realloc. If
+ it turns out that the heap was created with malloc checking and the
+ user has requested it malloc_set_state just calls __malloc_check_init
+ again to enable it. On the other hand, reusing such a heap without
+ further malloc checking is safe. */
+static int disallow_malloc_check;
+
/* Activate a standard set of debugging hooks. */
void
__malloc_check_init()
{
+ if (disallow_malloc_check) {
+ disallow_malloc_check = 0;
+ return;
+ }
+ using_malloc_checking = 1;
__malloc_hook = malloc_check;
__free_hook = free_check;
__realloc_hook = realloc_check;
@@ -4041,7 +4061,7 @@ int mALLOPt(param_number, value) int param_number; int value;
functions. */
#define MALLOC_STATE_MAGIC 0x444c4541l
-#define MALLOC_STATE_VERSION (0*0x100l + 0l) /* major*0x100 + minor */
+#define MALLOC_STATE_VERSION (0*0x100l + 1l) /* major*0x100 + minor */
struct malloc_state {
long magic;
@@ -4060,24 +4080,20 @@ struct malloc_state {
unsigned int max_n_mmaps;
unsigned long mmapped_mem;
unsigned long max_mmapped_mem;
+ int using_malloc_checking;
};
Void_t*
mALLOC_GET_STATe()
{
- mchunkptr victim;
struct malloc_state* ms;
int i;
mbinptr b;
- ptmalloc_init();
- (void)mutex_lock(&main_arena.mutex);
- victim = chunk_alloc(&main_arena, request2size(sizeof(*ms)));
- if(!victim) {
- (void)mutex_unlock(&main_arena.mutex);
+ ms = (struct malloc_state*)mALLOc(sizeof(*ms));
+ if (!ms)
return 0;
- }
- ms = (struct malloc_state*)chunk2mem(victim);
+ (void)mutex_lock(&main_arena.mutex);
ms->magic = MALLOC_STATE_MAGIC;
ms->version = MALLOC_STATE_VERSION;
ms->av[0] = main_arena.av[0];
@@ -4108,6 +4124,11 @@ mALLOC_GET_STATe()
ms->max_n_mmaps = max_n_mmaps;
ms->mmapped_mem = mmapped_mem;
ms->max_mmapped_mem = max_mmapped_mem;
+#if defined _LIBC || defined MALLOC_HOOKS
+ ms->using_malloc_checking = using_malloc_checking;
+#else
+ ms->using_malloc_checking = 0;
+#endif
(void)mutex_unlock(&main_arena.mutex);
return (Void_t*)ms;
}
@@ -4123,6 +4144,9 @@ mALLOC_SET_STATe(msptr) Void_t* msptr;
int i;
mbinptr b;
+#if defined _LIBC || defined MALLOC_HOOKS
+ disallow_malloc_check = 1;
+#endif
ptmalloc_init();
if(ms->magic != MALLOC_STATE_MAGIC) return -1;
/* Must fail if the major version is too high. */
@@ -4160,6 +4184,15 @@ mALLOC_SET_STATe(msptr) Void_t* msptr;
mmapped_mem = ms->mmapped_mem;
max_mmapped_mem = ms->max_mmapped_mem;
/* add version-dependent code here */
+ if (ms->version >= 1) {
+#if defined _LIBC || defined MALLOC_HOOKS
+ /* Check whether it is safe to enable malloc checking. */
+ if (ms->using_malloc_checking && !using_malloc_checking &&
+ !disallow_malloc_check)
+ __malloc_check_init ();
+#endif
+ }
+
(void)mutex_unlock(&main_arena.mutex);
return 0;
}